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Hyper-fidelity (HxF) depletion of pebble bed reactors (PBRs) is the capability to model depletion for every pebble while accounting for motion through the core. Previous HxF work demonstrated feasibility to deplete hundreds of thousands of stationary pebbles concurrently within reasonable timeframes. This work illustrates the second step towards HxF, coupling depletion with a discrete motion scheme. The model assumes an ordered bed with pebbles occupying fixed positions. Motion is simplified as discrete since pebbles move in straight lines from one set position to another. The methodology was implemented in Serpent 2, combined with its transport and depletion capabilities. Ad-hoc routines were developed ensuring compatibility with domain decomposition and pebble recirculation after each pass based on discharge criteria and fresh pebble insertion. Capabilities of HxF with discrete motion are demonstrated using a full-scale high-temperature gas-cooled reactor model. Specifically, an approach to equilibrium is performed, and example results are shown for in-core and discarded pebbles. The data illustrates how HxF provides unique insights into PBR fuel, producing information on statistical distributions rather than average values only, as obtained by traditional methods that rely on spectral zoning for depletion. Knowledge of these distributions can greatly improve analysis and assessment of PBRs. [ABSTRACT FROM AUTHOR]

Hyper-fidelity (HxF) depletion of pebble bed reactors (PBRs) is the capability to model depletion for every pebble while accounting for motion through the core. Previous HxF work demonstrated feasibility to deplete hundreds of thousands of stationary pebbles concurrently within reasonable timeframes. This work illustrates the second step towards HxF, coupling depletion with a discrete motion scheme. The model assumes an ordered bed with pebbles occupying fixed positions. Motion is simplified as discrete since pebbles move in straight lines from one set position to another. The methodology was implemented in Serpent 2, combined with its transport and depletion capabilities. Ad-hoc routines were developed ensuring compatibility with domain decomposition and pebble recirculation after each pass based on discharge criteria and fresh pebble insertion. Capabilities of HxF with discrete motion are demonstrated using a full-scale high-temperature gas-cooled reactor model. Specifically, an approach to equilibrium is performed, and example results are shown for in-core and discarded pebbles. The data illustrates how HxF provides unique insights into PBR fuel, producing information on statistical distributions rather than average values only, as obtained by traditional methods that rely on spectral zoning for depletion. Knowledge of these distributions can greatly improve analysis and assessment of PBRs. [ABSTRACT FROM AUTHOR]

This work introduces scheduling algorithms to maximize the expected number of independent tasks that can be executed on a parallel platform within a given budget and under a deadline constraint. The main motivation for this problem comes from imprecise computations, where each job has a mandatory part and an optional part, and the objective is to maximize the number of optional parts that are successfully executed, in order to improve the accuracy of the results. The optional parts of the jobs represent the independent tasks of our problem. Task execution times are not known before execution; instead, the only information available to the scheduler is that they obey some (unknown) probability distribution. The scheduler needs to acquire some information before deciding for a cutting threshold: instead of allowing all tasks to run until completion, one may want to interrupt long-running tasks at some point. In addition, the cutting threshold may be reevaluated as new information is acquired when the execution progresses further. This work presents several algorithms to determine a good cutting threshold, and to decide when to re-evaluate it. In particular, we use the Kaplan-Meier estimator to account for tasks that are still running when making a decision. The efficiency of our algorithms is assessed through an extensive set of simulations with various budget and deadline values, and ranging over 13 probability distributions. In particular, the AutoPerSurvival(40%,0.005) strategy is proved to have a performance of 77% compared to the upper bound even in the worst case. This shows the robustness of our strategy. [ABSTRACT FROM AUTHOR]

Background: We developed SmartRub® powered by iQati®, an electronic device composed of a wristband and an alcohol-based handrub pocket-sized dispenser that measures and provides feedback on the duration of hand friction and the volume poured during each hand hygiene action. We aimed to assess the accuracy of SmartRub®. Methods: The specificity, sensitivity, positive and negative predictive values (PPV and NPV) of SmartRub® were assessed in a 3-phased experiment: (1) laboratory-controlled conditions with volunteers; (2) pre-planned clinical path with volunteers and (3) real clinical conditions with healthcare workers. The accuracy of SmartRub® was evaluated by quantifying its ability to correctly capture true hand hygiene actions and to not record other actions performed while wearing the device. Results: In the laboratory, 7 volunteers performed 816 actions. Overall sensitivity was 94.1% (95% CI 91.4–96.2%) with a PPV of 99.0% (95% CI 97.3–99.6%) and specificity was 99.0% (95% CI 97.5–99.7%) with a NPV of 94.4% (95% CI 91.9–96.1%). During the pre-planned clinical path phase, 13 volunteers performed 98 planned paths and a total of 967 actions were performed. Overall sensitivity was 94.6% (95% CI 92.2–96.5%) with a PPV of 84.3% (95% CI 81.6–86.7%) and specificity was 82.4% (95% CI 78.7–85.7%) with a NPV of 93.9% (95% CI 91.3–95.7%). During the real clinical conditions phase, 17 healthcare workers were observed for a total of 15 h and 3 min while they performed 485 actions. Sensitivity was 96.8% (95% CI 93.8–98.6%) with a PPV of 98.3% (95% CI 95.6–99.3%) and specificity was 98.3% (95% CI 95.7–99.5%) with a NPV of 96.8% (95% CI 93.9–98.4%). Conclusions: Smartrub® is a highly reliable device for capturing hand hygiene actions under a range of conditions, from the laboratory to clinical care activities. [ABSTRACT FROM AUTHOR]

Dense tensor decompositions have been widely used in many signal processing problems including analyzing speech signals, identifying the localization of signal sources, and many other communication applications. Computing these decompositions poses major computational challenges for big datasets emerging in these domains. CANDECOMP/PARAFAC (CP) and Tucker formulations are the prominent tensor decomposition schemes heavily used in these fields, and the algorithms for computing them involve applying two core operations, namely tensor-times–matrix and tensor-times–vector multiplication, which are executed repetitively within an iterative framework. In the recent past, efficient computational schemes using a data structure called dimension tree, are employed to significantly reduce the cost of these two operations, through storing and reusing partial results that are commonly used across different iterations of these algorithms. This framework has been introduced for sparse CP and Tucker decompositions in the literature, and a recent work investigates using an optimal binary dimension tree structure in computing dense Tucker decompositions. In this paper, we investigate finding an optimal dimension tree for both CP and Tucker decompositions. We show that finding an optimal dimension tree for an N-dimensional tensor is NP-hard for both decompositions, provide faster exact algorithms for finding an optimal dimension tree in O (3 N) time using O (2 N) space for the Tucker case, and extend the algorithm to the case of CP decomposition with the same time and space complexities. [ABSTRACT FROM AUTHOR]

Résumé Les complications neurologiques touchant les patients atteints de la maladie de Scheuermann sont rares mais graves. Nous présentons trois cas de patients atteints de maladie de Scheuermann, avec des déficits neurologiques sévères, dus à une ischémie médullaire causée par la compression d’une artère radiculomédullaire par une hernie discale thoracique (deux cas) et une hernie discale lombaire (un cas). Aucun traitement chirurgical n’a été réalisé en raison de l’absence de compression médullaire directe et du caractère irréversible de l’ischémie médullaire. Ces jeunes patients gardent des séquelles neurologiques sévères. Une prise en charge plus précoce aurait pu prévenir ces déficits neurologiques définitifs. Une IRM médullaire avec séquence de diffusion et ADC (coefficient apparent de diffusion) devrait être réalisée en urgence devant le moindre signe de souffrance médullaire. [ABSTRACT FROM AUTHOR]

Pebble bed reactors, either gas-cooled or fluoride-cooled, are among the most promising advanced reactor concepts with active development worldwide. The relatively small size of the pebbles and the fact that they are continuously recirculated makes the task of simulating fuel burnup particularly challenging. Most solutions proposed thus far suggest dividing the core into spectral zones within which fuel composition is assumed uniform, ignoring differences between the different pebbles in the zone. This work suggests that it is possible with current computing tools and with relatively modest computing resources to perform depletion of pebble bed reactors by depleting each pebble individually. The feasibility of this approach, named hyper-fidelity depletion, is demonstrated using a simplified model that assumes static pebbles in a regular lattice and employing the Monte Carlo code Serpent 2 that provides multiple features suitable for hyper-fidelity depletion, among which the most important is domain decomposition. The obtained results show that the spectral zone methods compared to hyper-fidelity can predict average trends, but are not adequate to determine distribution for quantities of interest such as burnup, fission products, etc. [ABSTRACT FROM AUTHOR]

Background: Neurological complications in Scheuermann's disease are rare but serious.Case Reports: We report three cases of severe neurological deficit due to medullar ischemia attributable to the compression of a radiculomedullar artery by thoracic (two cases) and lumbar (one case) disc herniations associated with Scheuermann's disease. They were not treated surgically because of the absence of direct spinal cord compression or definitive spinal cord ischemia. Those young patients still have severe neurological damage. An earlier management could have prevented them.Conclusion: When doubting about any compressive sign, MRI should be performed with diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) sequences in emergency. [ABSTRACT FROM AUTHOR]

The traditional single-level checkpointing method suffers from significant overhead on large-scale platforms. Hence, multilevel checkpointing protocols have been studied extensively in recent years. The multilevel checkpoint approach allows different levels of checkpoints to be set (each with different checkpoint overheads and recovery abilities), in order to further improve the fault tolerance performance of extreme-scale HPC applications. How to optimize the checkpoint intervals for each level, however, is an extremely difficult problem. In this paper, we construct an easy-to-use two-level checkpoint model. Checkpoint level 1 deals with errors with low checkpoint/recovery overheads such as transient memory errors, while checkpoint level 2 deals with hardware crashes such as node failures. Compared with previous optimization work, our new optimal checkpoint solution offers two improvements: (1) it is an online solution without requiring knowledge of the job length in advance, and (2) it shows that periodic patterns are optimal and determines the best pattern. We evaluate the proposed solution and compare it with the most up-to-date related approaches on an extreme-scale simulation testbed constructed based on a real HPC application execution. Simulation results show that our proposed solution outperforms other optimized solutions and can improve the performance significantly in some cases. Specifically, with the new solution the wall-clock time can be reduced by up to 25.3 percent over that of other state-of-the-art approaches. Finally, a brute-force comparison with all possible patterns shows that our solution is always within $1$ percent of the best pattern in the experiments. [ABSTRACT FROM PUBLISHER]

ABSTRACT Introduction: Acid α-glucosidase deficiency, that is, Pompe disease, is a glycogenosis for which enzyme replacement therapy (ERT) is available. It is not known whether patients diagnosed at an asymptomatic stage should be treated to prevent progression of the disease. Methods: We investigated 7 patients with asymptomatic Pompe disease identified from the French Pompe registry. Results: The patients had a mean age of 45 (range 24-75) years, a median follow-up duration of 2 (range 1-22) years, and normal clinical examination, pulmonary function tests (PFTs), and echocardiography. All presented with at least 1 subclinical abnormality, including hyperCKemia, vacuolar myopathy, and muscle MRI abnormalities, suggesting that subclinical myopathy was present in all cases. Conclusions: Asymptomatic Pompe disease may remain clinically silent for decades, and affected patients should be monitored closely for overt myopathy using clinical examination, PFTs, and muscle MRI to determine when to start ERT. Muscle Nerve 51: 884-889, 2015 [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the impact of fault prediction techniques on checkpointing strategies. We extend the classical first-order analysis of Young and Daly in the presence of a fault prediction system, characterized by its recall and its precision. In this framework, we provide optimal algorithms to decide whether and when to take predictions into account, and we derive the optimal value of the checkpointing period. These results allow us to analytically assess the key parameters that impact the performance of fault predictors at very large scale. [Copyright &y& Elsevier]

One has a large workload that is 'divisible'-its constituent work's granularity can be adjusted arbitrarily-and one has access to p remote worker computers that can assist in computing the workload. How can one best utilize the workers? Complicating this question is the fact that each worker is subject to interruptions (of known likelihood) that kill all work in progress on it. One wishes to orchestrate sharing the workload with the workers in a way that maximizes the expected amount of work completed. Strategies are presented for achieving this goal, by balancing the desire to checkpoint often-thereby decreasing the amount of vulnerable work at any point-vs. the desire to avoid the context-switching required to checkpoint. Schedules must also temper the desire to replicate work, because such replication diminishes the effective remote workforce. The current study demonstrates the accessibility of strategies that provably maximize the expected amount of work when there is only one worker (the case p=1) and, at least in an asymptotic sense, when there are two workers (the case p=2); but the study strongly suggests the intractability of exact maximization for p≥2 computers, as work replication on multiple workers joins checkpointing as a vehicle for decreasing the impact of work-killing interruptions. We respond to that challenge by developing efficient heuristics that employ both checkpointing and work replication as mechanisms for decreasing the impact of work-killing interruptions. The quality of these heuristics, in expected amount of work completed, is assessed through exhaustive simulations that use both idealized models and actual trace data. [ABSTRACT FROM AUTHOR]

By measuring the ocular pulse amplitude (OPA), the dynamic contour tonometer (DCT) assesses intraocular pressure (IOP). Hypothesizing that OPA is characteristic for the IOP when considered with the systemic arterial blood pressure, we assumed the ratio of ocular and arterial pulsation amplitudes is larger in glaucoma patients. Bi-ocular DCT-OPA assessment was synchronized with arterial pulsations using Finapres® technology, thereby enabling blood pressure determination for each corresponding IOP value every 0.01 s for 12 s. Based on measurements and calculations in 10 healthy subjects and 11 glaucoma patients, we conclude that the ratio of the OPA and blood pressure variances is a strong glaucoma diagnostic indicator, thereby justifying further investigation. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: To describe muscle involvement on whole-body MRI scans in adult patients at different stages of late-onset Pompe disease. Twenty patients aged 37 to 75 were examined. Five were bedridden and required ventilatory support. Axial and coronal T1 turbo-spin-echo sequences were performed on 1.5T or 3T systems. MRI was scored for 47 muscles using Mercuri’s classification. Whole-body scans were obtained with a mean in-room time of 29min. Muscle changes consisted of internal bright signals of fatty replacement without severe retraction of the muscles’ corpus. Findings were consistent with previous descriptions of spine extensors and pelvic girdle, but also provided new information on recurrent muscle changes particularly in the tongue and subscapularis muscle. Moreover thigh involvement was more heterogeneous than previously described, in terms of distribution across muscles as well as with respect to the overall clinical presentation. Whole-body MRI provides a very evocative description of muscle involvement in Pompe disease in adults. [Copyright &y& Elsevier]

Abstract: One has a large computational workload that is “divisible” (its constituent tasks’ granularity can be adjusted arbitrarily) and one has access to p remote computers that can assist in computing the workload. How can one best utilize the computers? Two features complicate this question. First, the remote computers may differ from one another in speed. Second, each remote computer is subject to interruptions of known likelihood that kill all work in progress on it. One wishes to orchestrate sharing the workload with the remote computers in a way that maximizes the expected amount of work completed. We deal with three versions of this problem. The simplest version ignores communication costs but allows computers to differ in speed (a heterogeneous set of computers). The other two versions account for communication costs, first with identical remote computers (a homogeneous set of computers), and then with computers that may differ in speed. We provide exact expressions for the optimal work expectation for all three versions of the problem – via explicit closed-form expressions for the first two versions, and via a recurrence that computes this optimal value for the last, most general version. [Copyright &y& Elsevier]

Mapping applications onto parallel platforms is a challenging problem, even for simple application patterns such as pipeline or fork graphs. Several antagonist criteria should be optimized for workflow applications, such as throughput and latency (or a combination). In this paper, we consider a simplified model with no communication cost, and we provide an exhaustive list of complexity results for different problem instances. Pipeline or fork stages can be replicated in order to increase the throughput by sending consecutive data sets onto different processors. In some cases, stages can also be data-parallelized, i.e. the computation of one single data set is shared between several processors. This leads to a decrease of the latency and an increase of the throughput. Some instances of this simple model are shown to be NP-hard, thereby exposing the inherent complexity of the mapping problem. We provide polynomial algorithms for other problem instances. Altogether, we provide solid theoretical foundations for the study of mono-criterion or bi-criteria mapping optimization problems. [ABSTRACT FROM AUTHOR]

In this paper, we explore the problem of mapping linear chain applications onto large-scale heterogeneous platforms. A series of data sets enter the input stage and progress from stage to stage until the final result is computed. An important optimization criterion that should be considered in such a framework is the latency, or makespan, which measures the response time of the system in order to process one single data set entirely. For such applications, which are representative of a broad class of real-life applications, we can consider one-to-one mappings, in which each stage is mapped onto a single processor. However, in order to reduce the communication cost, it seems natural to group stages into intervals. The interval mapping problem can be solved in a straightforward way if the platform has homogeneous communications: the whole chain is grouped into a single interval, which in turn is mapped onto the fastest processor. But the problem becomes harder when considering a fully heterogeneous platform. Indeed, we prove the NP-completeness of this problem. Furthermore, we prove that neither the interval mapping problem nor the similar one-to-one mapping problem can be approximated in polynomial time by any constant factor (unless P=NP). [ABSTRACT FROM AUTHOR]

Abstract: Min, Veeravalli, and Barlas have proposed strategies to minimize the overall execution time of one or several divisible loads on a heterogeneous linear network, using one or more installments [Han Min Wong, Bharadwaj Veeravalli, Scheduling divisible loads on heterogeneous linear daisy chain networks with arbitrary processor release times, IEEE Trans. Parallel Distrib. Syst. 15 (3) (2004) 273–288; Han Min Wong, Bharadwaj Veeravalli, Gerassimos Barlas, Design and performance evaluation of load distribution strategies for multiple divisible loads on heterogeneous linear daisy chain networks, J. Parallel Distrib. Comput. 65 (12) (2005) 1558–1577]. We show using a very simple example that their approach does not always produce a solution and that, when it does, the solution is often suboptimal. We also show how to find an optimal scheduling for any instance, once the number of installments per load is given. Finally, we formally prove that under a linear cost model, as in both the above-mentioned references, an optimal schedule has an infinite number of installments. Therefore such a cost model should not be used to design practical multi-installment algorithms. [Copyright &y& Elsevier]

Abstract: Mapping applications onto parallel platforms is a challenging problem, that becomes even more difficult when platforms are heterogeneous — nowadays a standard assumption. A high-level approach to parallel programming not only eases the application developer’s task, but it also provides additional information which can help realize an efficient mapping of the application. In this paper, we discuss the mapping of pipeline skeletons onto different types of platforms: Fully Homogeneous platforms with identical processors and interconnection links; Communication Homogeneous platforms, with identical links but different-speed processors; and finally, Fully Heterogeneous platforms. We assume that a pipeline stage must be mapped on a single processor, and we establish new theoretical complexity results for different mapping policies: a mapping can be required to be one-to-one (a processor is assigned at most one stage), or interval-based (a processor is assigned an interval of consecutive stages), or fully general. In particular, we show that determining the optimal interval-based mapping is NP-hard for Communication Homogeneous platforms, and this result assesses the complexity of the well-known chains-to-chains problem for different-speed processors. We provide several efficient polynomial heuristics for the most important policy/platform combination, namely interval-based mappings on Communication Homogeneous platforms. These heuristics are compared to the optimal result provided by the formulation of the problem in terms of the solution of an integer linear program, for small problem instances. [Copyright &y& Elsevier]

Abstract: In this paper, we assess the impact of heterogeneity on scheduling independent tasks on master-slave platforms. We assume a realistic one-port model where the master can communicate with a single slave at any time. We target both on-line and off-line scheduling problems, and we focus on simpler instances where all tasks have the same size. While such on-line problems can be solved in polynomial time on homogeneous platforms, we show that there does not exist any optimal deterministic algorithm for heterogeneous platforms. Whether the source of heterogeneity comes from computation speeds, or from communication bandwidths, or from both, we establish lower bounds on the competitive ratio of any deterministic algorithm. We provide such bounds for the most important objective functions: the minimization of the makespan (or total execution time), the minimization of the maximum response time (difference between completion time and release time), and the minimization of the sum of all response times. Altogether, we obtain nine theorems which nicely assess the impact of heterogeneity on on-line scheduling. For off-line scheduling, we prove several result for problems with release dates, either optimality or NP-hardness. These theoretical contributions are complemented on the practical side by the implementation of several heuristics on a small but fully heterogeneous MPI platform. Our results show the superiority of those heuristics which fully take into account the relative capacity of the communication links. [Copyright &y& Elsevier]

Abstract: This paper is devoted to scheduling a large collection of independent tasks onto heterogeneous clusters. The tasks depend upon (input) files which initially reside on a master processor. A given file may well be shared by several tasks. The role of the master is to distribute the files to the processors, so that they can execute the tasks. The objective for the master is to select which file to send to which slave, and in which order, so as to minimize the total execution time. The contribution of this paper is twofold. On the theoretical side, we establish complexity results that assess the difficulty of the problem. On the practical side, we design several new heuristics, which are shown to perform as efficiently as the best heuristics in [H. Casanova, A. Legrand, D. Zagorodnov, F. Berman, Heuristics for scheduling parameter sweep applications in Grid environments, in: Ninth Heterogeneous Computing Workshop, IEEE Computer Society Press, Silver Spring, MD, 2000, pp. 349–363; H. Casanova, A. Legrand, D. Zagorodnov, F. Berman, Using simulation to evaluate scheduling heuristics for a class of applications in Grid environments, Research Report RR-1999-46, LIP, ENS Lyon, France, 1999] although their cost is an order of magnitude lower. [Copyright &y& Elsevier]

The article focuses on the problem of redistributing data on homogeneous and heterogeneous rings of processors. After each invocation of a load-balancing mechanism, the problem develops in several applications. Variations either in the resource performances or in the system/application requirements, necessitates data to be redistributed between participating processors to better balance the current load. Algorithms that aim at optimizing the data redistribution are provided, both for unidirectional and bidirectional rings. The optimality of the proposed algorithms in all cases has been proven.

Examines the use of algorithm to implement automatic partitioning of parallel loops with parallelepiped-shaped tiles. Analysis on the cumulative footprint of the tile; Determination of optimal tile shape through heuristics; Use of hierarchical memory systems in dealing with parallel doall loops.

This work investigates different orificing strategies in sodium fast reactors and their application to a reference standing-wave Breed-and-Burn (B&B) core. Through analytic means, the standard method of static integral orificing is shown to be infeasible in the reference core. Using simplified physical models, a novel Mixed-Integer Linear Programming (MILP) formulation is proposed to design whole-core assembly-level orificing schemes according to constraints on various operating conditions, including peak and average temperatures, mass flowrates, flow velocities, and outlet temperature profiles. After highlighting the major assumptions employed and quantifying their impacts, the MILP formulation is used to assess two alternative methods of assembly orificing, namely static grid plate and variable orificing. These two methods of orificing are found to be suitable to B&B cores, and their sensitivities to various constraints are examined. Ultimately the use of variable orificing is found to be the most desirable from the perspectives of flexibility and ability to cope with difficult constraints, although it may be the most difficult of the three methods to implement in a realistic core design. [ABSTRACT FROM AUTHOR]

• Biallelic mutations in TNXB can be a cause of myopathy. • Muscular weakness associates with articular and connective tissue alterations. • Tenascin X reduction in serum and skeletal muscle is present. Tenascin-X, is an extracellular matrix glycoprotein expressed in skin, muscle, tendons, and blood vessels with an anti-adhesive function. Biallelic Tenascin-X mutations cause classical-like Ehlers-Danlos syndrome. We report a 46-year-old woman with slowly progressive weakness of the lower limbs and myalgia from age 28 years. In the past she had Raynaud's phenomenon, multiple sprains and joint dislocations, conjunctival haemorrhages and a colonic perforation during colonoscopy. Neurologic examination showed moderate asymmetric proximal and axial muscular weakness, distal amyotrophy of 4 limbs, moderate skin hyperextensibility, and hypermobility of distal joints of fingers. Whole body Magnetic Resonance Imaging showed symmetric fatty infiltration of thigh and leg muscles, with predominant atrophy of thighs. Next Generation Sequencing revealed two pathogenic TNXB variants, g.32024681C> G , c.7826–1G> C , and g.32016181dup, c.9998dupA, p.(Asn3333Lysfs*35). Western Blot and immunofluorescence studies confirmed a marked Tenascin-X reduction in both patient's serum and muscle. Here we further detail the clinical and genetic spectrum of a patient with classical-like Ehlers-Danlos syndrome and prominent muscle involvement. [ABSTRACT FROM AUTHOR]

Soil temperature has been recognized as a property that strongly influences a myriad of hydro-biogeochemical processes and reflects how various properties modulate the soil thermal flux. In spite of its importance, our ability to acquire soil temperature data with high spatial and temporal resolution and coverage is limited because of the high cost of equipment, the difficulties of deployment, and the complexities of data management. Here we propose a new strategy that we call distributed temperature profiling (DTP) for improving the characterization and monitoring near-surface thermal properties through the use of an unprecedented number of laterally and vertically distributed temperature measurements. We developed a prototype DTP system, which consists of inexpensive, low-impact, low-power, and vertically resolved temperature probes that independently and autonomously record soil temperature. The DTP system concept was tested by moving sequentially the system across the landscape to identify near-surface permafrost distribution in a discontinuous permafrost environment near Nome, Alaska, during the summertime. Results show that the DTP system enabled successful acquisition of vertically resolved profiles of summer soil temperature over the top 0.8 m at numerous locations. DTP also enabled high-resolution identification and lateral delineation of near-surface permafrost locations from surrounding zones with no permafrost or deep permafrost table locations overlain by a perennially thawed layer. The DTP strategy overcomes some of the limitations associated with – and complements the strengths of – borehole-based soil temperature sensing as well as fiber-optic distributed temperature sensing (FO-DTS) approaches. Combining DTP data with co-located topographic and vegetation maps obtained using unmanned aerial vehicle (UAV) and electrical resistivity tomography (ERT) data allowed us to identify correspondences between surface and subsurface property distribution and in particular between topography, vegetation, shallow soil properties, and near-surface permafrost. Finally, the results highlight the considerable value of the newly developed DTP strategy for investigating the significant variability in and complexity of subsurface thermal and hydrological regimes in discontinuous permafrost regions. [ABSTRACT FROM AUTHOR]

• X-linked EDMD may present with camptocormia and minimal contractures. • Muscle biopsy with immunohistochemistry is pivotal in atypical myopathies. • Whole body MRI will allow to recognize new cases. Emery–Dreifuss muscular dystrophy is an early-onset, slowly progressive myopathy characterized by the development of multiple contractures, muscle weakness and cardiac dysfunction. We present here the case of a 65-year-old male patient with a 20 year history of slowly progressive camptocormia, bradycardia and shortness of breath. Examination showed severe spine extensor and neck flexor muscle weakness with slight upper limb proximal weakness. Cardiologic assessment revealed slow atrial fibrillation. Whole body MRI demonstrated adipose substitution of the paravertebral, limb girdle and peroneal muscles as well as the tongue. Emerin immunohistochemistry on patient muscle biopsy revealed the absence of nuclear envelope labeling confirmed by Western Blot. Genetic analysis showed a hemizygous duplication of 5 bases in exon 6 of the EMD, emerin, gene on the X chromosome. This is an unusual presentation of X-linked Emery–Dreifuss muscular dystrophy with adult onset, predominant axial muscles involvement and minimal joint contractures. Diagnosis was prompted by the analysis of emerin on muscle biopsy. [ABSTRACT FROM AUTHOR]

• aCGH is an important diagnostic tool for the genetic screening of early onset myopathies. • RALGAPA1 deficiency leads GLUT4 overexpression in human striated muscle cells. • GLUT4 overexpression is potentially linked to glycogen storage in muscle tissue. Early onset myopathies are a clinically and histologically heterogeneous monogenic diseases linked to approximately 90 genes. Molecular diagnosis is challenging, especially in patients with a mild phenotype. We describe a 26-year-old man with neonatal hypotonia, motor delay and seizures during infancy, and non-progressive, mild muscular weakness in adulthood. Serum Creatine kinase level was normal. Whole-body muscle MRI showed thin muscles, and brain MRI was unremarkable. A deltoid muscle biopsy showed glycogen storage. WGS revealed a de novo 1.4 Mb-deletion of chromosome 14, confirmed by Array-CGH. This microdeletion causes the loss of ten genes including RALGAPA1, encoding for RalA, a regulator of glucose transporter 4 (GLUT4) expression at the membrane of myofibers. GLUT4 was overexpressed in patient's muscle. Here we highlight the importance to search for chromosomal alterations in the diagnostic workup of early onset myopathies. [ABSTRACT FROM AUTHOR]

Background and purpose: CAV3 gene mutations, mostly inherited as an autosomal dominant trait, cause various skeletal muscle diseases. Clinical presentations encompass proximal myopathy, distal myopathy, or isolated persistent high creatine kinase (CK) with a major overlapping phenotype. Methods: Twenty‐three patients with CAV3 symptomatic mutations, from 16 different families, were included in a retrospective cohort. Mean follow‐up duration was 24.2 ± 15.0 years. Clinical and functional data were collected during the follow‐up. The results of muscle imaging, electroneuromyography, muscle histopathology, immunohistochemistry, and caveolin‐3 Western blot analysis were also compiled. Results: Exercise intolerance was the most common phenotype (52%). Eighty percent of patients had calf hypertrophy, and only 65% of patients presented rippling. One patient presented initially with camptocormia. A walking aid was required in only two patients. Electroneuromyography was mostly normal. CK level was elevated in all patients. No patient had cardiac or respiratory impairment. Muscle imaging showed fatty involvement of semimembranosus, semitendinosus, rectus femoris, biceps brachialis, and spinal muscles. Almost all (87%) of the biopsies were abnormal but without any specific pattern. Whereas a quarter of patients had normal caveolin‐3 immunohistochemistry results, Western blots disclosed a reduced amount of the protein. We report nine mutations, including four not previously described. No phenotype–genotype correlation was evidenced. Conclusions: Caveolinopathy has diverse clinical, muscle imaging, and histological presentations but often has limited functional impact. Mild forms of the disease, an atypical phenotype, and normal caveolin‐3 immunostaining are pitfalls leading to misdiagnosis. [ABSTRACT FROM AUTHOR]

• We introduce a model and analysis fro the performance or rigid, moldable and grid-shaped applications subject to failures. • We analytically determine the optimal number of failures that should be tolerated before relinquishing the allocation. • We compare the performance of checkpoint/restart and ABFT. • We provide an extended set of experimental results to assess the performance of all application types. This paper compares the performance of different approaches to tolerate failures for applications executing on large-scale failure-prone platforms. We study (i) R i g i d applications, which use a constant number of processors throughout execution; (ii) M o l d a b l e applications, which can use a different number of processors after each restart following a fail-stop error; and (iii) G r i d S h a p e d applications, which are moldable applications restricted to use rectangular processor grids (such as many dense linear algebra kernels). We start with checkpoint/restart, the de-facto standard approach. For each application type, we compute the optimal number of failures (i.e. that maximizes the yield of the application) to tolerate before relinquishing the current allocation and waiting until a new resource can be allocated, and we determine the optimal yield that can be achieved. For G r i d S h a p e d applications, we also investigate Application Based Fault Tolerance (ABFT) techniques and perform the same analysis, computing the optimal number of failures to tolerate and the associated yield. We instantiate our performance model with realistic applicative scenarios and make it publicly available for further usage. We show that using spare nodes grants a much better yield than currently used strategies that restart after each failure. Moreover, the yield is similar for R i g i d , M o l d a b l e and G r i d S h a p e d applications, while the optimal number of failures to tolerate is very high, even for a short wait time in between allocations. Finally, M o l d a b l e applications have the advantage to restart less frequently than R i g i d applications. [ABSTRACT FROM AUTHOR]

Introduction: The main objective of this study was to describe muscle involvement on whole-body magnetic resonance imaging scans in adults at different stages of glycogen-storage disease type III (GSDIII).Methods: Fifteen patients, 16-59 years of age, were examined on a 3-T system. The examinations consisted of coronal and axial T1-weighted images or fat images with a Dixon technique, and were scored for 47 muscles using Mercuri's classification. Muscle changes consisted of internal bright signals of fatty replacement.Results: Distribution across muscles showed predominant signal alteration in the lower limbs and postural muscles. This finding is consistent with the overall clinical presentation of GSDIII and the results of heatmap scores. Review of the MRI scans provided new information regarding recurrent muscle changes, particularly in the soleus, gastrocnemius medial head, and thoracic extensor muscles.Discussion: Whole-body muscle imaging provides clinically relevant information regarding muscle involvement in GSDIII. A severity score may contribute to improved patient management. Muscle Nerve, 2019. [ABSTRACT FROM AUTHOR]

Inverse semigroups and completely regular semigroups share some nice properties and in a certain sense, they are the top success stories in semigroup theory. Therefore a reasonable goal is to find other classes of regular semigroups with the same nice shared properties and try to replicate the successful structure theories achieved for those two classes. Perhaps surprisingly, the semigroup literature is mute on examples of other classes of regular semigroups with the same nice properties, while semigroupists, for decades, voiced the metamathematical conviction of the hopelessness of such a goal. Our guess is that many have tried that approach, but always failed, thus unable to publish (the muteness of the literature) and convinced that the path leads to nowhere (the metamathematical conviction). The aim of this paper is to provide some mathematical content for that metamathematical conviction. In his celebrated theorem, K. Arrow wrote down the nice properties a voting system should have and then went on to prove that no system has those properties. We follow a similar path by writing down the nice common properties of inverse semigroups and of completely regular semigroups, and then show that, under some constraints, any variety having those nice properties is contained in one of the other two (if not in both). The proof of this theorem is by exhaustion: all possible varieties (under certain constraints) are written down, and each one is tested regarding the possession of the nice properties. Many pass the test, but then all of them turn out to be varieties of inverse or completely regular semigroups. This proof requires thousands of lemmas and was only possible because we used ProverX, a system aimed at playing in automated reasoning the same role GAP or MAGMA plays in symbolic computation. The paper ends with some problems for experts in semigroups, equational logic and computer science. [ABSTRACT FROM AUTHOR]

The article briefly discusses research papers that are contained within the section, titled "Algorithm Design and Scheduling Techniques (Realistic Platform Models) for Heterogeneous Clusters," of this issue. The purpose of these papers is to explore the impact of platform heterogeneity on the design and evaluation of new algorithms, such as, distributed algorithms and scheduling algorithms. One paper by Ligang He and his colleagues discusses two new workload allocation strategies for large-scale heterogeneous platforms. The paper "On the Distribution of Sequential Jobs in Random Brokering for Heterogeneous Computational Grids," by Vandy Berten and colleagues, focuses on resource brokering for scheduling sequential jobs onto a grid platform. In their article, "Multiple Job Scheduling in a Connection-Limited Data Parallel System," authors Alessandro Amoroso and Keith Marzullo describe a new method for scheduling jobs in a distributed system.

Editorial. Provides a background on the special issue of the volume ten, numbers two and three, 2000 edition of the periodical 'Parallel Processing Letters,' which focuses on developments in the field of compiling for parallel computers. Selection of research papers presented during the eighth workshop on compilers for parallel computers held in France; Classification of papers published in the periodical.

The paraspinal region encompasses all tissues around the spine. The regional anatomy is complex and includes the paraspinal muscles, spinal nerves, sympathetic chains, Batson's venous plexus and a rich arterial network. A wide variety of pathologies can occur in the paraspinal region, originating either from paraspinal soft tissues or the vertebral column. The most common paraspinal benign neoplasms include lipomas, fibroblastic tumours and benign peripheral nerve sheath tumours. Tumour-like masses such as haematomas, extramedullary haematopoiesis or abscesses should be considered in patients with suggestive medical histories. Malignant neoplasms are less frequent than benign processes and include liposarcomas and undifferentiated sarcomas. Secondary and primary spinal tumours may present as midline expansile soft tissue masses invading the adjacent paraspinal region. Knowledge of the anatomy of the paraspinal region is of major importance since it allows understanding of the complex locoregional tumour spread that can occur via many adipose corridors, haematogenous pathways and direct contact. Paraspinal tumours can extend into other anatomical regions, such as the retroperitoneum, pleura, posterior mediastinum, intercostal space or extradural neural axis compartment. Imaging plays a crucial role in formulating a hypothesis regarding the aetiology of the mass and tumour staging, which informs preoperative planning. Understanding the complex relationship between the different elements and the imaging features of common paraspinal masses is fundamental to achieving a correct diagnosis and adequate patient management. This review gives an overview of the anatomy of the paraspinal region and describes imaging features of the main tumours and tumour-like lesions that occur in the region. Key points: Paraspinal tumours can invade the epidural/intercostal spaces, mediastinum, pleura and retroperitoneum. Paraspinal tumours originate either from the spine or the paraspinal soft tissues. Paraspinal soft tissue tumours can invade the adjacent vertebra or rib. MRI is needed to assess the anatomical location of paraspinal lesions. Image-guided biopsy is required to determine the histological nature of the mass. [ABSTRACT FROM AUTHOR]

This paper focuses on energy minimization for the mapping and scheduling of real-time workflows under reliability constraints. Workflow instances are input periodically to the system. Each instance is composed of several tasks and must complete execution before the arrival of the next instance, and with a prescribed reliability threshold. While the shape of the dependence graph is identical for each instance, task execution times are stochastic and vary from one instance to the next. The reliability threshold is met by executing several replicas for each task. The target platform consists of identical processors equipped with Dynamic Voltage and Frequency Scaling (DVFS) capabilities. A different frequency can be assigned to each task replica to save energy, but it may have negative effect on the deadline and reliability target. This difficult tri-criteria mapping and scheduling problem (energy, deadline, reliability) has been studied only recently for workflows with arbitrary dependence constraints. We investigate new mapping and scheduling strategies based upon layers in the task graph. These strategies better balance replicas across processors, thereby decreasing the time overlap between different replicas of a given task, and saving energy. We compare these strategies with two state-of-the-art approaches and a reference baseline on a variety of benchmark workflows. Our best heuristics achieve an average energy gain of 60% over the competitors and of 82% over the baseline. • Tri-criteria mapping and scheduling problem for real-time workflows of arbitrary shape. • First general solution without any limitation on the number of replicas used. • Innovative solution based upon layers of the workflow outperforms competitors. [ABSTRACT FROM AUTHOR]

Applications structured as Directed Acyclic Graphs (DAGs) of tasks occur in many domains, including popular scientific workflows. DAG scheduling has thus received an enormous amount of attention. Many of the popular DAG scheduling heuristics make scheduling decisions based on path lengths. At large scale compute platforms are subject to various types of failures with non-negligible probabilities of occurrence. Failures that have recently received increased attention are “silent errors,” which cause data corruption. Tolerating silent errors is done by checking the validity of computed results and possibly re-executing a task from scratch. The execution time of a task then becomes a random variable, and so do path lengths in a DAG. Unfortunately, computing the expected makespan of a DAG (and equivalently computing expected path lengths in a DAG) is a computationally difficult problem. Consequently, designing effective scheduling heuristics in this context is challenging. In this work, we propose an algorithm that computes a first order approximation of the expected makespan of a DAG when tasks are subject to silent errors. We find that our proposed approximation outperforms previously proposed approaches both in terms of approximation error and of speed. [ABSTRACT FROM AUTHOR]

Recently, the benefits of co-scheduling several applications have been demonstrated in a fault-free context, both in terms of performance and energy savings. However, large-scale computer systems are confronted by frequent failures, and resilience techniques must be employed for large applications to execute efficiently. Indeed, failures may create severe imbalance between applications and significantly degrade performance. In this article, we aim at minimizing the expected completion time of a set of co-scheduled applications. We propose to redistribute the resources assigned to each application upon the occurrence of failures, and upon the completion of some applications, in order to achieve this goal. First, we introduce a formal model and establish complexity results. The problem is NP-complete for malleable applications, even in a fault-free context. Therefore, we design polynomial-time heuristics that perform redistributions and account for processor failures. A fault simulator is used to perform extensive simulations that demonstrate the usefulness of redistribution and the performance of the proposed heuristics. [ABSTRACT FROM AUTHOR]

An abstract of the article "Advances in imaging for the diagnosis and disease monitoring of Pompe disease" by Robert-Yves Carlier is presented.

Errors have become a critical problem for high-performance computing. Checkpointing protocols are often used for error recovery after fail-stop failures. However, silent errors cannot be ignored, and their peculiarity is that such errors are identified only when the corrupted data is activated. To cope with silent errors, we need a verification mechanism to check whether the application state is correct. Checkpoints should be supplemented with verifications to detect silent errors. When a verification is successful, only the last checkpoint needs to be kept in memory because it is known to be correct. In this paper, we analytically determine the best balance of verifications and checkpoints so as to optimize platform throughput. We introduce a balanced algorithm using a pattern with p checkpoints and q verifications, which regularly interleaves both checkpoints and verifications across same-size computational chunks. We show how to compute the waste of an arbitrary pattern, and we prove that the balanced algorithm is optimal when the platform MTBF (mean time between failures) is large in front of the other parameters (checkpointing, verification and recovery costs).We conduct several simulations to show the gain achieved by this balanced algorithm for well-chosen values of p and q, compared with the base algorithm that always perform a verification just before taking a checkpoint (p = q = 1), and we exhibit gains of up to 19%. [ABSTRACT FROM AUTHOR]

Background Late-onset Pompe disease is characterized by progressive skeletal myopathy followed by respiratory muscle weakness, typically leading to loss of ambulation and respiratory failure. In this population, enzyme replacement therapy (ERT) with alglucosidase alfa has been shown to stabilize respiratory function and improve mobility and muscle strength. Muscle pathology and glycogen clearance from skeletal muscle in treatmen t -naïve adults after ERT have not been extensively examined. Methods This exploratory, open-label, multicenter study evaluated glycogen clearance in muscle tissue samples collected pre- and post- alglucosidase alfa treatment in treatment-naïve adults with late-onset Pompe disease. The primary endpoint was the quantitative reduction in percent tissue area occupied by glycogen in muscle biopsies from baseline to 6 months. Secondary endpoints included qualitative histologic assessment of tissue glycogen distribution, secondary pathology changes, assessment of magnetic resonance images (MRIs) for intact muscle and fatty replacement, and functional assessments. Results Sixteen patients completed the study. After 6 months of ERT, the percent tissue area occupied by glycogen in quadriceps and deltoid muscles decreased in 10 and 8 patients, respectively. No changes were detected on MRI from baseline to 6 months. A majority of patients showed improvements on functional assessments after 6 months of treatment. All treatment-related adverse events were mild or moderate. Conclusions This exploratory study provides novel insights into the histopathologic effects of ERT in late-onset Pompe disease patients. Ultrastructural examination of muscle biopsies demonstrated reduced lysosomal glycogen after ERT. Findings are consistent with stabilization of disease by ERT in treatment-naïve patients with late-onset Pompe disease. [ABSTRACT FROM AUTHOR]

Abstract: This article reviews briefly three important aspects of tonometry: physics, physiology, and glaucoma. With respect to the physical principles of tonometry, deformation of the globe is a key component: force tonometers measure intraocular pressure (IOP) by deforming the globe whereas pressure tonometers do not. Pressure tonometers can provide measurements that are closer to absolute pressure than force tonometers. Tonometry is a physiological measurement that evaluates IOP over time by assessing pulsation in consideration of the pressure gradient from the cornea to the optic nerve. It seems that the outflow characteristics of the trabecular meshwork also modify the pulse amplitude. When diagnosing glaucoma, tonometry alone does not adequately discriminate between normal and diseased eyes. A long-term measurement may be desirable but this, in turn, evokes new problems. Finally, lowering the IOP improves the blood flow in the optic nerve head. [Copyright &y& Elsevier]

This work revisits I/O bandwidth-sharing strategies for HPC applications. When several applications post concurrent I/O operations, well-known approaches include serializing these operations (▪) or fair-sharing the bandwidth across them (FairShare). Another recent approach, I/O-Sets, assigns priorities to the applications, which are classified into different sets based upon the average length of their iterations. We introduce several new bandwidth-sharing strategies, some of them simple greedy algorithms, and some of them more complicated to implement, and we compare them with existing ones. Our new strategies do not rely on any a-priori knowledge of the behavior of the applications, such as the length of work phases, the volume of I/O operations, or some expected periodicity. We introduce a rigorous framework, namely steady-state windows , which enables to derive bounds on the competitive ratio of all bandwidth-sharing strategies for three different objectives: minimum yield, platform utilization, and global efficiency. To the best of our knowledge, this work is the first to provide a quantitative assessment of the online competitiveness of any bandwidth-sharing strategy. This theory-oriented assessment is complemented by a comprehensive set of simulations, based upon both synthetic and realistic traces. The main conclusion is that two of our simple and low-complexity greedy strategies significantly outperform ▪, FairShare and I/O-Sets, and we recommend that the I/O community would implement them for further assessment. • Design of novel I/O bandwidth-sharing strategies that go beyond First Come First Served and Fair Share. • First competitiveness analysis of I/O bandwidth-sharing strategies. • Comprehensive simulation campaign using an extensive set of application scenarios. [ABSTRACT FROM AUTHOR]

• MRI with MR angiography and Zero Echo Time (ZTE) sequences were as effective as CT-scan for pre-surgical assessment of NHO's features and their relationship to vessels and nerves. • Nerves are more often identified in MRI than in CT. • MRI with MR angiography should be considered as a valuable alternative CT for pre-surgical assessment of NHO, particularly in case of anterior NHO, if nerve involvement is suspected or for patients with iodine contrast media allergy. Neurogenic heterotopic ossification (NHO) of the hip is a frequent complication of spinal cord injuries, often requiring surgical management. Pre-surgical imaging assessment is essential, usually with computed tomography (CT)-scan. We aimed to compare magnetic resonance imaging (MRI) and CT for pre-surgical imaging assessment of the NHO, particularly for their relationships with vessels and nerves. This prospective study included consecutive patients who underwent surgery for NHO from July 2019 to April 2022. All patients had CT angiography and MRI including Zero Echo Time and TRICKS sequences. Radiologists used standardized reports for CT and MRI to evaluate NHO and their features, bone mineralization, and relation to the arteries, veins and nerves. Agreement between pre-surgical CT and MRI was evaluated. Twenty-four patients (mean age: 53.5 ± 12.2 years) were included, among which 7 had bilateral NHO (31 hips). NHO were anterior in 15/31 hips (48 %), multifragmented in 25/31 hips (81 %). Mild and significant demineralization was most frequent. Gutter and tunnel were reported in 11.1 % of the arteries. Nerves were more often identified in MRI than in CT-scan. Agreement coefficients between CT and MRI were excellent for NHO location (0.95) and implantation (0.92), good for fragmentation (0.70), contact with joint capsule (0.66), bone mineralization (0.74), and relation to arteries (0.85), veins (0.76), sciatic nerve (0.7) and moderate for femoral nerve (0.47). MRI exhibited a good agreement with CT for pre-surgical assessment of NHO of the hip, especially to evaluate their relationships with the arteries, veins and sciatic nerve. Femoral nerves were more often identified in MRI than in CT-scan. [ABSTRACT FROM AUTHOR]

Background: Pompe disease is a rare neuromuscular disorder caused by a deficiency of a lysosomal enzyme, acid α‐glucosidase. Macroglossia is a classic clinical sign of several inherited myopathies and has also been reported to occur progressively in late‐onset Pompe disease (LOPD). Methods: We describe patients with LOPD and macroglossia included in the French national Pompe disease registry. Clinical, functional, and radiological data were collected during periodic follow‐up and analyzed retrospectively. These cases were compared with 15 previously reported cases. Results: Five patients, three females and two males, aged 71–88 years, were included in this study. All but one of the patients suffered from symptoms related to macroglossia before the diagnosis of Pompe disease. Three had localized tongue atrophy and one had significant localized tongue hypertrophy which led to glossectomy 10 years before diagnosis. Two patients had severe dysphagia, one of whom underwent gastrostomy for enteral nutritional support. One patient experienced the persistence of numerous sleep apneas despite nocturnal bilevel positive airway pressure (BiPAP) ventilation. All our patients had dysarthria, and two required speech therapy. Four patients had a tongue hypersignal on magnetic resonance imaging (MRI) T1 sequences. Conclusions: Detection of macroglossia should be part of the clinical diagnosis and follow‐up of patients with LOPD, with a careful evaluation of its main consequences. Macroglossia can have severe functional impacts on speech, swallowing, and sleep. Whole‐body MRI with facial sections may facilitate the early diagnosis of Pompe disease with the "bright tongue sign". [ABSTRACT FROM AUTHOR]